Comparison between selective and nonselective nitric oxide synthase inhibition and phenylephrine in normal and endotoxic swine

OBJECTIVE To compare the cardiopulmonary and peripheral circulatory effects of the nonselective nitric oxide synthase (NOS) inhibitor NG-nitro-L-arginine methyl ester (L-NAME) to the more selective inducible NOS inhibitor S-methylisothiourea (SMT) and to phenylephrine (PE) in endotoxic and normal swine. DESIGN Prospective, randomized, unblinded study. SETTING Research laboratory of academic medical center. SUBJECTS Nonanesthetized, sedated, mechanically ventilated, minimally invasive swine model. INTERVENTIONS Animals received either lipopolysaccharide (LPS, LPS groups) or equivalent volume of saline (normal groups). LPS animals were further randomized into four groups when mean arterial pressure (MAP) had dropped to